The present invention relates to a new and improved method of automatically changing textile bobbins on a cantilevered bobbin chuck of a textile winding machine, and further concerns a new and improved bobbin changing apparatus for implementing the aforesaid method. The bobbin change apparatus is of the type comprising a bobbin tube gripper axially movable in the take-off of doffing direction arranged within two end positions on a rigidly arranged bobbin chuck for taking-off a bobbin tube supporting a wound bobbin package and for transferring it onto a supporting bolt of bobbin package transporting device held in readiness.
Changing devices for removing or taking-off full bobbin packages from a cantilevered bobbin chuck and for transferring them onto a bolt of a bobbin creel held in readiness are known already to the art. One prior art device of this type consists of a trolley which is movable on rails along a row of winding machines and which is pivotable about its vertical axis, and provided with a number of bobbin package take-off devices corresponding to the number of bobbin packages to be simultaneously taken-off. The bobbin take-off devices consist of a bobbin tube gripper movable along a straight horizontal path. The bobbin tube gripper is moved from a starting position linearly towards the bobbin chuck for gripping the bobbin tube. In this arrangement the bobbin tube gripper is arranged on and coaxially with respect to the gripper movement path. Upon gripping the full bobbin package tube the gripper is moved in the opposite direction along the same path until the full bobbin package tube sufficiently clears the bobbin chuck. Subsequently the trolley is pivoted about its vertical axis in such a manner that the full bobbin packages can be shifted onto a bobbin creel provided with supporting bolts by a reverse movement of the bobbin tube gripper. Thereafter, the gripper and the trolley are again moved back to their starting position, so that the changing device is ready for the next take-off of full bobbin packages.
A disadvantage of a changing device of this type resides in the fact that the gripper is arranged coaxially on its path of movement. It thus is necessary to pivot the gripper through 180.degree. in order that the bobbin package can be transferred to the bobbin creel.
A further drawback is present in that no empty tube can be placed onto the empty gripper since at the position where such an empty tube could be placed there is present the bobbin creel.
Furthermore, neither a thread cutting and suction device, nor a thread re-piecing device are combined with the changing device, so that for a fully mechanically operating bobbin change device the following operations are to be additionally executed by hand:
a. Cutting and sucking off the thread.
b. Placing the empty tube onto the bobbin chuck.
c. Threading-up the thread onto the empty tube placed onto and accelerated upon the bobbin chuck.